Just an FYI on the air over electric brake controller, I had one of them first in my Volvo and hated it. I didn't like how it applied the trailer brakes, it was not smooth at all. I pulled it out after one trip and put in a good quality electronic controller.
I have a Prodgey 2, (sp) controller on the Freightliner, it works but not as well as the Hayes controller on other trucks that I have driven. From what I have been told and experienced when I drove a truck equipped with the Hayes unit you have to mess with it a bit to get the adjustment correct from there on it works very well.
The Pete has so much more braking power then the Freightliner as it has tandem axles other then keeping the trailer behind the truck in very slippery conditions the trailer brakes are pretty much unneeded. In fact I drove the Freightliner towing the trailer for over a 1,000 in the mountains once before I found out that the trailer brakes had not been working, a broken wire left them useless and I didn't really notice any difference in stopping power of course during that 1,000 miles I was lucky and didn't have a panic stop situation or have to drive on slippery surfaces where the trailer may have wanted to pass the truck.